Wagons of various types have been used by farmers since the earliest beginnings of agriculture. Modern grain wagons, to which the present invention relates, generally consist of a relatively deep, four-sided container box supported on a wheel mounted frame. A trailer tongue, mounted at the front of the frame, allows the wagon to be pulled by farm tractors. trucks or other towing vehicles. Most grain wagons have relatively deep container boxes to facilitate the carrying of a large volume of grain. However, the depth of a grain box can make unloading of grain by manual methods very strenuous and time consuming. To overcome this drawback, various unloading devices are incorporated with many grain wagons. Some wagons utilize agricultural augers to move the grain out of the box. This is generally accomplished by a horizontal floor auger positioned inside and at the bottom of the box and a vertical auger positioned outside the box along the wall at one end. The horizontal auger moves the grain to the end of the box where the inlet to the vertical auger is located. The vertical auger then raises the grain out of the box onto a waiting truck or other grain receptacle.
Another method for unloading a grain box has been to angle the lower portion of the side walls of the box toward the center of the box. In this arrangement, the walls of the box becomes essentially a sloping floor, which detects all of the grain towards a central point at the bottom of the box. By providing a hopper at the bottom of the box, or a side door in one of the walls near the bottom of the box, the grain may be discharged through the door or hopper opening by use of the force of gravity.
A problem with the double auger arrangement described above is the substantial costs of providing a wagon with two augers and the necessary power sources. Another problem with a double auger grain box is the volume and weight of the augers which limits the amount of grain that can be added to the box. Double auger arrangements also tend to increase maintenance problems since cleaning the box in and around the area occupied by the augers is difficult and time consuming. Yet another problem with the double auger arrangement is that the vertical auguer must necessarily be placed at the end of the box to which the horizontal auger is directed. In many situations, it would be desirable to position the vertical auger at different locations within the box, depending upon the loading requirements for a particular operation. Also, the vertical auger increases the overall length or width of the wagon.
Although a gravity box eliminates some of the problem associated with the use of double augers, it has the great disadvantage of allowing unloading only near the bottom of the box. In many work situations, such as loading grain into a waiting truck, the grain must be elevated above the height of the grain wagon in order to accomplish the job. In this type of application, the gravity box is of little use, and the grain must be transported either manually or with the aid of some external conveyor system.
Thus, it can be seen that a need exists for an agricultural grain wagon which can be unloaded by a device capable of raising the grain to an elevation above the top of the grain box and which is also capable of being positioned to discharge grain from any of the four sides of the grain box. The device should not occupy excessive space within the grain box and should be easily removed to allow cleaning of the grain box. In addition, the grain wagon should be capable of being operated as a gravity box during certain farming applications when elevated loading is not required. And finally, the wagon should allow maximum grain volume, yet not exceed overall safe width for transporting the wagon on the road.